Refrigerant



A. mPajzepted July 7, 1931 UNITED STATES.

PATENT OFFICE LEONARD KAY WRIGHT, OF JACKSON HEIGHTS, NEW.YORK

REFRIGERANT No Drawing.

increasing the cost of production, and sometimes interfering with the efiicient operation of the apparatus. Other refrigerants have had a corrosive effect on metals, and in order to avoid a corrosion of the metal parts of the refrigerating apparatus with'which they contact, have necessitated apparatus constructed of expensive alloys or compounds.

Still other refrigerants have had a tendency to decompose when subjected to operating conditions, and have also tended to break down lubricants.

An object of this invention is to provide a refrigerant having a low pressure of condensation and a low boiling point.

Another 'object is to provide a refrigerant that is inert on lubricants and has a non-corrosive action on metals.

Yet another object of this inventionis to devise a refrigerating process whereby a maximum refrigerating effect is obtained with a minimum expenditure of energy.

A still further object is to devise a refrigerating process that is simple, and can be carried out in an inexpensive apparatus.

-To accomplish theabove and other important objects, as will appear herein, my invention in general comprises a refrigerant that has a low pressure of condensation, a relatively low boiling point at atmospheric pressure, 40 and that is non-corrosive on metals and inert on lubricants.-

I have found in my investigations that allylene is adapted for use as a refrigerant. Allylene exists in two isomers, symmetrical allylene (or symmetrical allylene propadiene) having the formula CH C CH5, and unsymmetrical allylene (or methyl acetylene), having the formula CH CE Ch. The

. unsymmetrical is particularly adapted for refrigeration.

pressure also permits the use of rotary com:

sors, an oil, seal'is dependedupon to maintain Application filed October 7, 1927. Serial No. 224,766.

Both of the isomers have a high latent heat of vaporization, and a low specific heat as compared to its latent heat. This, high ratio of latent to specific heat tends to produce a maximum refrigerating effect per cycle of Bi operation.

At atmospheric pressure the symmetrical allylene boils at 17 F., while the'unsymmetrical form boils at 27.5 C. These boiling points are sufficiently low to obtain any 00 temperature desired in a refrigeration process, whether for household use or for industrial purposes.

Allylene gas liquefies at atmospheric temperature under a pressure of from .40 to ounds, which permits of the use of this rerigerant in apparatus provided with ordinary tubing and piping. This is a distinct advantage over some of the prior'refrigerants used whlch have required hlgh pressure to effect condensation of the gas, for it has been necessary heretofore to employ extra heavy piping to prevent any explosion or leakage of the refrigerant, from the system. .This low 76 pressors. Although rotary compressors have been used on high pressure refrigerants, it is extremely desirable to use refrigerants having lower pressures, for with such compresproper compression. The amount of power necessary in my refrigeration rocess is therefore conside rabl decreased rom numerous processes hereto ore used.

' The unsymmetrical allylene has a critical temperature of 127.9 (1., which is adequately high to insure a condensation at all temperatures-where condensation would be required.

- As'allylene has a non-corrosive action on all metals, iron, steel, copper, brass, bronze, or any metal, or compounds or alloys, can be used in the construction of the apparatus, thus effecting a material economy in the manufacture of the apparatus.

The refrigerant allylene is stable under all working conditions encountered in a refrigerating process, and does not tend to decompose over a period of operation or when subjected to undue heat. This renders it particularly adaptable for use in an adsorptlon process,

where the application of heat is necessary. A number of refrigerants heretofore employed, While capable of operation in a compression process, have not been satisfactory in an adsorption apparatus.

Allylene has an odor, which renders it easy to detect in case of a leakage from the apparatus, but inasmuch as the gas is noninjurious to health, there is little danger of harm resulting from such a leakage.

Should a leak occur, or should air remain in the system prior to the introduction of the refrigerant, there is no danger of allylene combining with the atmosphere to form gases or acids, that would be injurious to the system. It has no affinity for water, and any aqueous vapor that might enter the system may be drained therefrom. Inasmuch as numerous refrigerants heretofore employed have had an affinity for air, and more particularly for water, thus forming acids or gases injurious to the system, this property of allylene is a distinct advance over the previous refrigerants.

As above stated, allylene may be used in either an adsorption or compression rocess. The apparatus that may be employe is extremely simple, and may take the conventional form.

In the former process, an adsorber-generator may be provided, containing a suitable adsorbent material, such as glaucosil, silica in the skeleton form, silica gel, carbon, activated carbon, or any other adsorbents. As allylene is soluble in alcohol or ether, these substances may be used as absorbents should the apparatus be of the absorption type. A pipe may conduct the gases driven off from the adsorbent, upon application of heat, to the condensor. Inasmuch asthe pressure of condensation of this substance is low for the high temperature at which condensation is effected, the condenser may be of light material, such as a simple honeycomb or automobile type of radiator, and may be air cooled, thus obviating the expensive and somewhat intricate water cooled condensers now generally necessary'with the refrigerants used. From the condenser, the liquefied refrigerant is conveyed by a pipe to a storage tank, Where the condensed allylene is held until the cooling cycle is commenced.

Heat is removed from the adsorbent, and the adsorbent ceases to give off the gas, its adsorptive capacity thus increasing. There is a. concomitant reduction in pressure in the adsorber-generator, and as the pressure in the condenser and storage tank is the maximum pressure obtained during the heating cycle,

the differential in pressure causes the liquefied allylene to pass through a pressure reduction valve and into an evaporating unit. As the refrigerant evaporates, heat from the surrounding medium is absorbed, producing the refrigerating effect. After evaporation the gaseous allyene passes to the adsorber-generator, where it is adsorbed, and the cycle repeated. Various modifications may of course be made in the apparatus herein described.

As above stated, allylene may be used in a compression apparatus of the conventional type including a compressor, condenser, receiver and evaporator, and suitable pressure valves and piping.

4 It is to be distinctly understood that the use of my invention is not to be limited in any way by the above description of apparatus.

From the foregoing it will be observed that I have provided an efficient refrigerant, that is capable of long and sustained use without deterioration, and one that is noncorrosive on metals and is inert on lubricants. The cost of producing my refrigerant is relatively small, and in view of its longevity is an economical refrigerant for use in any process. While it is particularly adapted as a refrigerant in an adsorption. machine it may also be efficiently employed in a compression apparatus. v 7

Where the word adsorption appears in the specification and claims, it is to be taken as covering absorption as well. The word allylene when unqualified herein covers both the symmetrical and unsymmetrical forms.

IVhile I have herein shown and described a particularly satisfactory compound and process for carrying out the invention, it will nevertheless be understood that the several salient features may be effected byother alternatives, and hence I accordingly reserve the right to resort to all such legitimate changes as may be fairly incorporated in the spirit and scope of the invention as claimed.

I claim as my invention:

1. A refrigerating process comprising adsorbing allylene, driving off the allylene from the adsorption agent, condensing the allylene, and evaporating the condensed allylene to produce refrigeration.

2. Arefrigerating process comprising adsorbing allylene, heating the adsorption agent to drive off the allylene, condensing the allylene, and evaporating the condensed refrigerant.

3. A process of refrigeration comprising taking up voiatilized allylene in a suitable agent, heating the agent to drive off the allylene, condensing the evolved allylene and reducing the pressure on the condensate to effect evaporation.

i. A refrigerating process comprising adsorbing symmetrical allyiene, driving off the symmetrical allylene from the adsorption agent. condensing the symmetrical allylene and evaporating the condensed symmetrical allylene to produce refrigeration.

5. A refri erating process comprising ad-- sorbing unsymmetrical allylene, driving off the unsymmetrical allylene from the adsorption agent, condensing the unsymmetrical allylene, and evaporating the condensed un- 5 symmetrical allylene to produce'refrigeration. I

In testimony whereof I afiix my signature.

LEONARD KAY WRIGHT. 

